Generation games … Mel Gibson as Kurt, Mark Wahlberg as Dusty, Will Ferrell as Brad and John Lithgow as Don in Daddy’s Home 2.
Photograph: Claire Folger/Paramount Pictures

It’s a funny thing – or rather an intensely and overwhelmingly unfunny thing – but this can be a moderately successful film until Mel Gibson shows up and opens his mouth. Or even just smiles. Then he’s a kind of grinning death’s-head of unfunny, toxically irradiating the entire film with poison rays of conceited non-charm. Like the recent and rather better movie A Bad Moms Christmas, this sequel franchises a hit comedy by bringing in the older generation. Brad (Will Ferrell) and Dusty (Mark Wahlberg) are the father and stepfather, who have agreed to be co-dads for their kids. But now their own fathers show up for the Christmas holidays. Naturally, reformed tough guy Dusty has an unreformed alpha dad: Kurt, played by Mel Gibson. Brad’s dad is Don (John Lithgow), a gentle soul. There’s some nice stuff here when Don shows how much he’s learned from therapeutic improv comedy classes and when Brad has to give his kid “the talk” about sex, and it turns into a loser tutorial in how to settle for the friend zone. But Mel Gibson shows up and puts the gamma rays of awfulness on it, time after time.